Samsung 840 Series SSDs debut with 21-nm NAND

Samsung's 830 Series is currently our favorite SSD. It's well-priced, has relatively low power consumption, and offers the most well-rounded performance of any solid-state drive we've tested. The drive's successor, the 840 Series, is expected to hit the market around the middle of next month. Samsung showed off the new drive, which comes in standard and Pro flavors, at an event in Seoul, Korea, today. AnandTech was on the scene and has the details.

Both members of the 840 Series family feature a new MDX controller that's reportedly based on the same architecture as the MCX chip in the 830 Series. The big difference with the 840 Series is the NAND, which is fabbed on a 21-nm process. The 830 Series uses 27-nm NAND.

Like most SSDs, the old drive uses MLC flash with two bits per cell. That's true for the 840 Series Pro, as well, but the standard model features TLC NAND that squeezes an extra bit into every cell. This TLC NAND is slower than the MLC stuff, according to Samsung, and its write-erase endurance should also be lower. Samsung isn't revealing specifics about longevity, though.

The 840 Series Pro is rated for 540MB/s sequential reads and 450MB/s writes, relatively modest upgrades over the 830 Series. Random read performance is purportedly up to 100k IOps, and random write performance has more than doubled from the previous generation, to 78k IOps. The standard model is rated for 540/330MB/s with sequential transfers and 98/70k IOps with random I/O.

AnandTech's initial review of the 840 Series Pro is positive, but we'll reserve judgement on the drive until we can run it through our test suite. Looks like the Pro will carry a sizable premium over the standard model. The 128GB and 256GB 840 Series drives are set to sell for $110 and $200, respectively, while the Pro models are supposed to cost $150 and $270 for those capacities. Samsung will offer 512GB versions of both drives and a 64GB variant of the Pro, as well.